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m-NITRANILINE

washed through water, is passed into the dark red pasty mass,
which is occasionally shaken.* The clinitrobenzene slowly
dissolves, whilst, at the same time, flakes of crystallised sulphur
are deposited. When the gas has been passing- for an hour the
flask is removed and heated on the water-bath fora few minutes.
After cooling, the liquid is again saturated with hydrogen
sulphide and then heated on the water-bath as before. When
the gas has been passing in a steady stream for fully two hours
the process is complete. Water is now added to the liquid until
nothing further is precipitated. The mixture is filtered at the
pump and washed with a little water. The solid residue is
transferred to a flask and shaken up with successive small
quantities of hot dilute hydrochloric acid and the liquid
decanted through the original filter. The nitraniline dissolves,
leaving the sulphur. When no more nitraniline is extracted
(this may be ascertained by adding ammonia in excess to
a portion of the acid solution, when no precipitate is formed),
the acid solution is somewhat concentrated, cooled, and con-
centrated ammonia added. The w-nitraniline is precipitated,
filtered when cold, and purified by recrystallisation from
boiling water. The filtrate from the nitraniline may be concen-
trated on the water-bath and a further small quantity obtained.
Yield, about 15 grams.

/ies. -Yellow needles;   m. p. 114;   b. p. 285.    With
tin and hydrochloric acid it is reduced to w-phenylenediamine,

m-Phenylenediamine. Dissolve 30 grams stannous chloride
(SnClo + 2! !,,()) in 50 c.c. cone, hydrochloric acid in a round flask
(}> litre) and gradually add 5 grams ;;/-nitraniline. The mixture
is heated on the water-bath until no precipitate is formed, on
adding water (\ hour). The liquid is diluted with 500 c.c.
water, heated nearly to boiling and a current of hydrogen
sulphide passed in until all the tin is precipitated as sulphide
(A - 4 hour). With this object a small quantity should be
filtered and tested from time to time by passing in hydrogen
sulphide. The precipitate is left overnight to subside, the clear
liquid decanted and the residue filtered at the pump through a